Electric terminal



Sept. 29, 19 31.

NYMAN ELECTRIC TERMINAL FiledS ept. '10, 1925 icq. 5

NVENTOR flaw/v00? -/Vy/v 9/v ATTORNEYS i -31) though mica can be procure i Patented Sept.- 29, 1931 umrso STATES. PATENT OFFICE 11.2mm N'num, or New Your, N. Y; assronoa 'ro nnmnmn commxsnn con- POBATION, 01' NEW YORK, N. Y.,

.L CORPORATION OF DELAWARE rmnc'rmc grammar.

. Application filed September 10, 1925. Serial No. 55,584.

' This invention relates to improvements in electrical terminals of the high tension type and particularl to a type of terminal adapted for lea ing high tension, hi h-fre- 1.; quency currents into electrostatic con ensers and other electrical apparatus.

With high tension leading-in terminals now in use, owing to the losses that occur due to the action of the high frequency currents upon the insulating media which are necessary for the support and maintenance of the terminal, considerable heat, frequently of a destructive character, is generated. The limitation or avoidance of such losses is one of the advantages of my-improved terminal.

' Another object of my invention is to provide a type of terminal, which is substantially constructed and at the same time embodies protective insulating surfaces of relatively re arge extent. I I

A further object of my invention is the rovision within the terminal of a long s ar ing or safety gap which is an indispensa le feature in the operation of a terminal of this 2:; sort. I

I prefer mica as the insulation for my terminal, but other dielectrics of similar properties may be used. Mica has proven to be the best material for purpose, al-

only in flat sheets and must therefore be employed in sheet form.

As experience shows that when an electric flux enters or leaves the surface of a flat di- F: electric more or less perpendicularly to that surface, losses will occur; while if the dielectric flux is made to pass substantially pirallel to the fiat surface, the insulation is tter and the resultant losses, the least; so in the construction of my improved terminal, I employ a flat disc or discs of mica, the plane of which extend in approximately the same direction as the electrostatic lines of force between surfaces or parts of my terminal, having a difference of electric potential.

The invention will be more fully explained by reference to the accompanying drawings which illustrate an embodiment thereof.

Figure 1 is a vertical section of a according to my invention;

terminal,

. v as a sparking or safety gap. "The function Figure 2 is a top view of the same; and- I Figure 3 is a diagram of the electrostatic field existing between an electrode and a casing or support therefor in my terminal.

The same numerals identify the same parts throughout.

' washers 8 and 9 against the disks 4 and 5 retain the mica discs 4 and 5 firmly 1n position, The edges of the nuts 6 and 7 are rounded for a reason that will appear later.

Encircling the rod 1 is a meta 11c ring 10, having a rounded protuberance or rib 11 on its inner surface. This ring also has a flange 12 to engage the edgeof an opening in the container or casing 13 which encloses a condenser or some other electric appliance. The mica discs 4 and 5 rest upon the edges or op osite ends of. the ring or sleeve 10,; being firm y secured-thereupon by the circular clam ing means or rings 14 and.15 which are provided with suitable apertures for the retaining screws'16 and 17. The rings 14 and 15 also have rounded edges, like the nuts 6 and 7, to

reduce the danger of discharge between the nuts and the clampin rings.

In Figure 3, the e ectrostatic field existing between the rod 1 and the internal surface of the surrounding tubular support 10 for the mica discs 4 and 5 is diagrammatically represented. The direction of the dielectric lines 4 is thus arallel to the surfaces of the insulatin at mica discs 4 and 5. B such dispositionofthe insulating material, insula tion losses due to the rapidly varying high frequency electric field are greatly diminished and heating effects become much less pronounced. On the inside of the sleeve or cylinder 10, the space between the rounded rib 11 and the central rod 1 separated therefrom is provided the sp1r1t or scope of my lnvention. For 1nstance, it is often advantageous for purposes of ventilation, to supply the upper disc 5 with a few perforations and thus lessen the two mica discs to become ionized and thus become conductive between the electrode 1 and hollow support or sleeve 10. .The discs or diaphragms 4 and 5 may be made up of several thin sheets or layers of mica, as. will be understood.

It is well known that any sharp edge will be the cause of a brush discharge and consequent sparkin at a voltage lower than a rounded edge. y rounding off the edges of the metallic ring 10 and the-rings 14 and 15,

together with the shoulders 3 of the sleeve 2,

the safety gap is confined to the space between the rib 11 and sleeve 2 and sparking at any other point is prevented.

Having described my invention, what I believe to be new and desire to secure and protect by Letters Patent of the United States 1s: 4

1. Aterminal comprising a hollow conductlve support, a conductor in the support, and an insulating diaphragmcarried by the sup.-

port through which the conductor passes, the

conductor and the support being shaped to provide a safety spark gap between them, and means for completing an enclosure for said spark gap. a

2. terminalcomprisinga hollow conductive support, a conductor in the support, and an insulating diaphragm carried by the su port through which the conductor passes, t 1e conductor and the support being shaped to provide may spark gap between them, said support having an internal rib forming one side of said gap, and means comprisin a diaphragm for completing an enclosure for said spark gap.

3. terminal comprising a hollow conductive support, a conductor in the support and an' insulating diaphragm ca'rried by the support through which the conductor passes, the support having an external flange to enable the terminal to be mounted, the support and conductor being shaped to provide a safety spark gap between them, and insulating means said spark gap.

4. A terminal comprising a hollow conductive support, a conductor in the support, and a pair of insulating diaphragms carried by tendency for the air in the space between the enclosed by the support, said diaphragms secured against the opposite ends of the support, the conductor passing through the diaphragms.

5. A terminal comprising a hollow conductive support, a conductor in the support, and a pair of insulating diaphragms carried by .the support the conductor passingthrough edges adjacent said rib.

7. A terminal comprising a hollow support, p

a conductor within the support, an insulating diaphragm carried by the sup ort through which the conductor passes, an an insulating member surrounding the conductor and adjacent to the diaphragm, the support 99 and conductor forming a protective spark gap said insulating diaphragm an member. 8. A terminal comprising a hollow support, a conductor within the support, a me- 9 tallic sleeve in the support around the conductor, a plurality of insulating diaphragms through which the conductor passes, the diaphragms being clamped to sald sup ort and against the sleeve, and a plurality o insulat ing sleevesaround the'conductor and adjacent to the insulating diaphragms. 9. A terminal comprisin a hollow conductive su port, a conductor in the support, an insulating diaphragm carried by the support through which the conductor passes, the support having an internal rounded rib to provide a safety spark gap-between the same and the conductor, said terminal havin no well defined edges adjacent said rib, an an additional diaphragm completing an enclosure for the said spark gap. J

In testimony w ereof I afiix my signature.

ALEXANDER NYMAN. 5

or completing an enclosure for the 

